Coupling adapter for a light bar



FIG. 1 is a perspective view of the new design for a coupling adapter for a light bar as seen from the top, rear, right side;

FIG. 2 is a perspective view thereof, as seen from the top, front, left side;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a front elevational view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is a top plan view thereof.

The broken lines in the drawings illustrate portions of the coupling adapter for a light bar and form no part of the claimed design. 

CLAIM The ornamental design for a coupling adapter for a light bar, as shown and described. 